Oath of Nixilis

When Oath of Nixilis enters the battlefield, you
may pay X life. If you do, Oath of Nixilis deals X
damage to each creature.
Whenever an opponent activates an ability of a planeswalker they control, that player loses 3 life
unless they sacrifice a nonland permanent or
discard a card.
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"Watch in despair, until all is dust and ashes."